Samuel Morse was born this day in 1791. Fifty years later he invented dashes and dots that spanned continents, crossed oceans and communicated with ships at sea. Those doing electrical work need communication, too. They need to know what's happening at the other end of a circuit that they're about to tap. "Hot or not?" That's the big question. Often they find out by trial and error, or yelling "Is it off yet?" Or listening for a radio to shut down. Or by running back and forth flipping switches (a system that messes up digital clocks and computers). But a new locator system now makes the process safe and easy. Just plug its transmitter into an outlet or light with a screw-in plug adapter, and run the receiver unit over the switches or fuses until it lights and beeps; there's your circuit! No guessing, no trial and error. For more tips, visit our Web site at onthehouse.com. And that's the On The House tip for today.